<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
          "DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <title>yapgvb.GraphBase</title>
  <link rel="stylesheet" href="epydoc.css" type="text/css"></link>
</head>
<body bgcolor="white" text="black" link="blue" vlink="#204080"
      alink="#204080">

<!-- =========== START OF NAVBAR =========== -->
<table class="navbar" border="0" width="100%" cellpadding="0" bgcolor="#a0c0ff" cellspacing="0">
  <tr valign="center">
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="yapgvb-module.html">Home</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="trees.html">Trees</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="indices.html">Index</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="help.html">Help</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar" align="right" width="100%">
      <table border="0" cellpadding="0" cellspacing="0">
      <tr><th class="navbar" align="center">
        <p class="nomargin">
          yapgvb
      </p></th></tr></table>
    </th>
  </tr>
</table>
<table width="100%" cellpadding="0" cellspacing="0">
  <tr valign="top">
    <td width="100%">
      <font size="-1"><b class="breadcrumbs">
        <a href="yapgvb-module.html">Package&nbsp;yapgvb</a> ::
        Class&nbsp;GraphBase
      </b></font></br>
    </td>
    <td><table cellpadding="0" cellspacing="0">
      <tr><td align="right"><font size="-2">[<a href="../private/yapgvb.GraphBase-class.html">show&nbsp;private</a>&nbsp;|&nbsp;hide&nbsp;private]</font></td></tr>
      <tr><td align="right"><font size="-2">[<a href="frames.html"target="_top">frames</a>&nbsp;|&nbsp;<a href="yapgvb.GraphBase-class.html" target="_top">no&nbsp;frames</a>]</font></td></tr>
    </table></td>
</tr></table>

<!-- =========== START OF CLASS DESCRIPTION =========== -->
<h2 class="class">Class GraphBase</h2>

<dl><dt><b>Known Subclasses:</b></dt>
<dd>
    <a href="yapgvb.Digraph-class.html"><code>Digraph</code></a>,
    <a href="yapgvb.Graph-class.html"><code>Graph</code></a></dd></dl>

<hr/>

GraphBase is the base class for Graph and Digraph. GraphBase should 
not be instantiated directly.
<hr/>


<!-- =========== START OF METHOD SUMMARY =========== -->
<table class="summary" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white">
<tr bgcolor="#70b0f0" class="summary">
  <th colspan="2">Method Summary</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#__init__" class="summary-sig-name"><code>__init__</code></a>(<span class=summary-sig-arg>self</span>,
          <span class="summary-sig-vararg">*args</span>,
          <span class="summary-sig-kwarg">**keywords</span>)</span></code>
<br />
GraphBase is a base class used by Graph and Digraph.</td></tr>
<tr bgcolor="#e8f0f8" class="group">
  <th colspan="2">&nbsp;&nbsp;&nbsp;&nbsp;Graph Definition</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#add_node" class="summary-sig-name"><code>add_node</code></a>(<span class=summary-sig-arg>self</span>,
          <span class=summary-sig-arg>name</span>,
          <span class="summary-sig-kwarg">**attributes</span>)</span></code>
<br />
Add a node to the graph.</td></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#add_edge" class="summary-sig-name"><code>add_edge</code></a>(<span class=summary-sig-arg>self</span>,
          <span class=summary-sig-arg>tail</span>,
          <span class=summary-sig-arg>head</span>)</span></code>
<br />
Create an edge between two nodes.</td></tr>
<tr bgcolor="#e8f0f8" class="group">
  <th colspan="2">&nbsp;&nbsp;&nbsp;&nbsp;Layout and Rendering</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#layout" class="summary-sig-name"><code>layout</code></a>(<span class=summary-sig-arg>self</span>,
          <span class=summary-sig-arg>engine</span>,
          <span class=summary-sig-arg>rendering_context</span>)</span></code>
<br />
Process the graph with one of the layout engines supplied by 
Graphviz.</td></tr>
<tr bgcolor="#e8f0f8" class="group">
  <th colspan="2">&nbsp;&nbsp;&nbsp;&nbsp;I/O</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#render" class="summary-sig-name"><code>render</code></a>(<span class=summary-sig-arg>self</span>,
          <span class=summary-sig-arg>outstream</span>,
          <span class=summary-sig-arg>format</span>,
          <span class=summary-sig-arg>rendering_context</span>)</span></code>
<br />
Render the graph to a file.</td></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#write" class="summary-sig-name"><code>write</code></a>(<span class=summary-sig-arg>self</span>,
          <span class=summary-sig-arg>output_stream_or_filename</span>)</span></code>
<br />
Output the graph in the dot language format.</td></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#read" class="summary-sig-name"><code>read</code></a>(<span class=summary-sig-arg>cls</span>,
          <span class=summary-sig-arg>input_stream_or_filename</span>)</span></code>
<br />
Read a graph from a dot file.    <i>(Class method)</i>
</td></tr>
<tr bgcolor="#e8f0f8" class="group">
  <th colspan="2">&nbsp;&nbsp;&nbsp;&nbsp;Boost.Graph Compatibility</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#from_bgl" class="summary-sig-name"><code>from_bgl</code></a>(<span class=summary-sig-arg>cls</span>,
          <span class=summary-sig-arg>bgraph</span>,
          <span class=summary-sig-arg>node_properties</span>,
          <span class=summary-sig-arg>edge_properties</span>)</span></code>
<br />
Translate a boost.python graph into a yapgvb graph.    <i>(Class method)</i>
</td></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><code><span class="summary-sig"><a href="yapgvb.GraphBase-class.html#to_bgl" class="summary-sig-name"><code>to_bgl</code></a>(<span class=summary-sig-arg>ygraph</span>,
          <span class=summary-sig-arg>node_properties</span>,
          <span class=summary-sig-arg>edge_properties</span>)</span></code>
<br />
Translate a graphviz graph into a boost.python graph.</td></tr>
</table><br />


<!-- =========== START OF PROPERTY SUMMARY =========== -->
<table class="summary" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white">
<tr bgcolor="#70b0f0" class="summary">
  <th colspan="2">Property Summary</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">rect</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#bb"><code>bb</code></a></b>: Bounding box of drawing in integer points.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#bgcolor"><code>bgcolor</code></a></b>: When attached to the root graph, this color is used as the background 
for entire canvas.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#center"><code>center</code></a></b>: If true, the drawing is centered in the output canvas.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#charset"><code>charset</code></a></b>: Specifies the character encoding used when interpreting string input 
as a text label.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">string</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#clusterrank"><code>clusterrank</code></a></b>: Mode used for handling clusters.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#colorscheme"><code>colorscheme</code></a></b>: This attribute specifies a color scheme namespace.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#comment"><code>comment</code></a></b>: Comments are inserted into output.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#compound"><code>compound</code></a></b>: If true, allow edges between clusters.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#concentrate"><code>concentrate</code></a></b>: If true, use edge concentrators.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#Damping"><code>Damping</code></a></b>: Factor damping force motions.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#defaultdist"><code>defaultdist</code></a></b>: This specifies the distance between nodes in separate connected 
components.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">int</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#dim"><code>dim</code></a></b>: Set the number of dimensions used for the layout.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#directed"><code>directed</code></a></b>: True if directed, False if not.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#dpi"><code>dpi</code></a></b>: This specifies the expected number of pixels per inch on a display 
device.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#epsilon"><code>epsilon</code></a></b>: Terminating condition.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#fontcolor"><code>fontcolor</code></a></b>: Color used for text.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#fontname"><code>fontname</code></a></b>: Font used for text.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#fontpath"><code>fontpath</code></a></b>: Directory list used by libgd to search for bitmap fonts if Graphviz 
was not built with the fontconfig library.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#fontsize"><code>fontsize</code></a></b>: Font size, in points, used for text.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#graph"><code>graph</code></a></b>: graph to which this belongs (parent, if a subgraph, otherwise 
self)</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#K"><code>K</code></a></b>: Spring constant used in virtual physical model.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#label"><code>label</code></a></b>: Text label attached to objects.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#labeljust"><code>labeljust</code></a></b>: Justification for cluster labels.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#labelloc"><code>labelloc</code></a></b>: Top/bottom placement of graph and cluster labels.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#landscape"><code>landscape</code></a></b>: If true, the graph is rendered in landscape mode.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#layers"><code>layers</code></a></b>: Specifies a linearly ordered list of layer names attached to the graph 
The graph is then output in separate layers.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#layersep"><code>layersep</code></a></b>: Specifies the separator characters used to split the layers attribute 
into a list of layer names.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#levelsgap"><code>levelsgap</code></a></b>: Specifies strictness of level constraints in neato when 
mode=&quot;hier&quot;.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">(x,y) or (x,y,z) tuple</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#lp"><code>lp</code></a></b>: Label position, in points.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#margin"><code>margin</code></a></b>: For graphs, this sets x and y margins of canvas, in inches.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">int</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#maxiter"><code>maxiter</code></a></b>: Sets the number of iterations used.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#mclimit"><code>mclimit</code></a></b>: Multiplicative scale factor used to alter the MinQuit (default = 8) 
and MaxIter (default = 24) parameters used during crossing 
minimization.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#mindist"><code>mindist</code></a></b>: Specifies the minimum separation between all nodes.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#mode"><code>mode</code></a></b>: Technique for optimizing the layout.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#model"><code>model</code></a></b>: This value specifies how the distance matrix is computed for the input 
graph.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#nodesep"><code>nodesep</code></a></b>: Minimum space between two adjacent nodes in the same rank, in 
inches.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#nojustify"><code>nojustify</code></a></b>: By default, the justification of multi-line labels is done within the 
largest context that makes sense.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#normalize"><code>normalize</code></a></b>: If set, normalize coordinates of final layout so that the first point 
is at the origin, and then rotate the layout so that the first edge is 
horizontal.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#nslimit"><code>nslimit</code></a></b></td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#nslimit1"><code>nslimit1</code></a></b></td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#ordering"><code>ordering</code></a></b>: If &quot;out&quot; for a graph G, and n is a node in G, then edges 
n-&gt;* appear left-to-right in the same order in which they are 
defined.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#orientation"><code>orientation</code></a></b>: Angle, in degrees, used to rotate node shapes.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">string</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#outputorder"><code>outputorder</code></a></b>: Specify order in which nodes and edges are drawn.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#overlap"><code>overlap</code></a></b>: Determines if and how node overlaps should be removed.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#pack"><code>pack</code></a></b>: This is true if the value of pack is &quot;true&quot; 
(case-insensitive) or a non-negative integer.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">string</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#packmode"><code>packmode</code></a></b>: This indicates the granularity and method used for packing (cf.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">pointf</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#page"><code>page</code></a></b>: Width and height of output pages, in inches.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">string</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#pagedir"><code>pagedir</code></a></b>: If the page attribute is set and applicable, this attribute specifies 
the order in which the pages are emitted.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#quantum"><code>quantum</code></a></b>: If quantum &gt; 0.0, node label dimensions will be rounded to integral 
multiples of the quantum.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">string</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#rankdir"><code>rankdir</code></a></b>: Sets direction of graph layout.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#ranksep"><code>ranksep</code></a></b>: In dot, this the gives desired rank separation, in inches.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#ratio"><code>ratio</code></a></b>: Sets the aspect ratio (drawing height/drawing width) for the 
drawing.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#remincross"><code>remincross</code></a></b>: If true and there are multiple clusters, run cross minimization a 
second time.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#resolution"><code>resolution</code></a></b>: This is a synonym for the dpi attribute.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#root"><code>root</code></a></b>: This specifies nodes to be used as the center of the layout and the 
root of the generated spanning tree.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">int</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#rotate"><code>rotate</code></a></b>: If 90, set drawing orientation to landscape.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">int</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#samplepoints"><code>samplepoints</code></a></b>: If the input graph defines the vertices attribute, and output is dot 
or xdot, this give the number of points used to represent circles and 
ellipses.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">int</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#searchsize"><code>searchsize</code></a></b>: During network simplex, maximum number of edges with negative cut 
values to search when looking for one with minimum cut value.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#sep"><code>sep</code></a></b>: Fraction to increase polygons (multiply coordinates by 1 + sep) for 
purposes of determining overlap.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">int</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#showboxes"><code>showboxes</code></a></b>: Print guide boxes in PostScript at the beginning of routesplines if 1, 
or at the end if 2.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">pointf</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#size"><code>size</code></a></b>: Maximum width and height of drawing, in inches.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#splines"><code>splines</code></a></b>: Controls how, and if, edges are represented.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">string</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#start"><code>start</code></a></b>: Parameter used to determine the initial layout of nodes.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#strict"><code>strict</code></a></b>: True if strict, False if not.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#stylesheet"><code>stylesheet</code></a></b>: A URL or pathname specifying an XML style sheet, used in SVG 
output.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#target"><code>target</code></a></b>: If the object has a URL, this attribute determines which window of the 
browser is used for the URL.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">boolean</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#truecolor"><code>truecolor</code></a></b>: If set explicitly to true or false, the value determines whether or 
not internal bitmap rendering relies on a truecolor color model or uses a 
color palette.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#URL"><code>URL</code></a></b>: Hyperlinks incorporated into device-dependent output.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">str</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#viewport"><code>viewport</code></a></b>: Clipping window on final drawing.</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">float</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#voro_margin"><code>voro_margin</code></a></b></td></tr><tr bgcolor="#e8f0f8" class="group">
  <th colspan="2">&nbsp;&nbsp;&nbsp;&nbsp;Graph Traversal</th></tr>
<tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#nodes"><code>nodes</code></a></b>: An iterator over all nodes in the graph</td></tr><tr><td align="right" valign="top" width="15%"><font size="-1">&nbsp;</font></td>
  <td><b><a href="yapgvb.GraphBase-class.html#edges"><code>edges</code></a></b>: An iterator of edges contained in the graph.</td></tr></table><br />


<!-- =========== START OF INSTANCE METHOD DETAILS =========== -->
<table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white">
<tr bgcolor="#70b0f0" class="details">
  <th colspan="2">Instance Method Details</th></tr>
</table>

<a name="add_node"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">add_node</span>(<span class=sig-arg>self</span>,
          <span class=sig-arg>name</span>=<span class=sig-default>None</span>,
          <span class="sig-kwarg">**attributes</span>)</span>
  </h3>
  <p>Add a node to the graph. If a node of this name exists already, it 
  will be returned and no new node will be created. If no name is 
  specified, a random (and probably unique) name will be assigned. The 
  keyword arguments are (attribute_name, value) pairs; this is a 
  shorthand equivalent to assigning attributes individually:</p>
  <p>n = mygraph.add_node('node_name', label=&quot;Hello World&quot;, 
  fontsize=48)</p>
  <p>is equivalent to:</p>
  n = mygraph.add_node('node_name') n.label = 'Hello World' n.fontsize 
  = 48
  <dl><dt></dt><dd>
  </dd></dl>
</td></tr></table>

<a name="add_edge"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">add_edge</span>(<span class=sig-arg>self</span>,
          <span class=sig-arg>tail</span>,
          <span class=sig-arg>head</span>)</span>
  </h3>
  Create an edge between two nodes. Returns the created edge 
  object.
  <dl><dt></dt><dd>
  </dd></dl>
</td></tr></table>

<a name="layout"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">layout</span>(<span class=sig-arg>self</span>,
          <span class=sig-arg>engine</span>,
          <span class=sig-arg>rendering_context</span>=<span class=sig-default>None</span>)</span>
  </h3>
  Process the graph with one of the layout engines supplied by 
  Graphviz.
  <dl><dt></dt><dd>
    <dl><dt><b>Parameters:</b></dt>
      <dd><code><b>engine</b></code> -
         Name of the layout engine. Possible values are 'fdp', 'twopi', 
        'neato', 'dot', 'circo'.
      <dd><code><b>rendering_context</b></code> -
         Leave this as None for now. It will be explained when I have 
        time to write more documentation ;-)
      </dd>
    </dl>
  </dd></dl>
</td></tr></table>

<a name="render"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">render</span>(<span class=sig-arg>self</span>,
          <span class=sig-arg>outstream</span>=<span class=sig-default>&lt;epydoc.imports._DevNull&nbsp;instance&nbsp;at&nbsp;0x2aaaab84b320&gt;</span>,
          <span class=sig-arg>format</span>=<span class=sig-default>None</span>,
          <span class=sig-arg>rendering_context</span>=<span class=sig-default>None</span>)</span>
  </h3>
  Render the graph to a file. layout must be called prior to 
  rendering.
  <dl><dt></dt><dd>
    <dl><dt><b>Parameters:</b></dt>
      <dd><code><b>outstream</b></code> -
         Either a filename or an open, writable file stream.
      <dd><code><b>format</b></code> -
         Desired file format. One of 'pic', 'jpg', 'ismap', 'gd', 
        'hpgl', 'ps2', 'plain-ext', 'wbmp', 'ps', 'mif', 'gif', 
        'canoncmap', 'fig', 'pcl', 'vtx', 'vrml', 'svgz', 'gd2', 'xdot', 
        'jpeg', 'cmapx', 'imap', 'png', 'plain', 'dia', 'mp', 'svg', 
        'dot'.
      <dd><code><b>rendering_context</b></code> -
         Leave this as None for now. It will be explained when I have 
        time to write more documentation ;-)
      </dd>
    </dl>
<p><b>Attention:</b> If you're writing a binary format, be sure to open outstream as a 
binary stream.
</p>

<p><b>Note:</b> If format is None (the default) and outstream is a filename, render 
will attempt to infer the correct format from the filename extension.
</p>

  </dd></dl>
</td></tr></table>

<a name="write"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">write</span>(<span class=sig-arg>self</span>,
          <span class=sig-arg>output_stream_or_filename</span>=<span class=sig-default>&lt;epydoc.imports._DevNull&nbsp;instance&nbsp;at&nbsp;0x2aaaab84b320&gt;</span>)</span>
  </h3>
  Output the graph in the dot language format. To render as an image, 
  use the render() method. To read a dot file, use the __init__ 
  constructor or the read() classmethod.
  <dl><dt></dt><dd>
  </dd></dl>
</td></tr></table>

<a name="to_bgl"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">to_bgl</span>(<span class=sig-arg>ygraph</span>,
          <span class=sig-arg>node_properties</span>=<span class=sig-default>[]</span>,
          <span class=sig-arg>edge_properties</span>=<span class=sig-default>[]</span>)</span>
  </h3>
  <p>Translate a graphviz graph into a boost.python graph.</p>
  The returned translation_map behaves like a dictionary of all 
  corresponding (boost_edge, yapgvb_edge), (yapgvb_edge, boost_edge), 
  (boost_vertex, yapgvb_node), and (yapgvb_node, boost_vertex) key/value 
  pairs.
  <dl><dt></dt><dd>
    <dl><dt><b>Parameters:</b></dt>
      <dd><code><b>node_properties</b></code> -
         A list of strings naming node properties to converted from 
        yapgvb to boost.
      <dd><code><b>edge_properties</b></code> -
         A list of strings naming edge properties to converted from 
        yapgvb to boost.
      </dd>
    </dl>
    <dl><dt><b>Returns:</b></dt>
      <dd>
        (bgraph, translation_map)
      </dd>
    </dl>
  </dd></dl>
</td></tr></table>

<a name="__init__"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">__init__</span>(<span class=sig-arg>self</span>,
          <span class="sig-vararg">*args</span>,
          <span class="sig-kwarg">**keywords</span>)</span>
    <br /><i>(Constructor)</i>
  </h3>
  GraphBase is a base class used by Graph and Digraph. Do not 
  instantiate it directly.
  <dl><dt></dt><dd>
  </dd></dl>
</td></tr></table>
<br />


<!-- =========== START OF CLASS METHOD DETAILS =========== -->
<table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white">
<tr bgcolor="#70b0f0" class="details">
  <th colspan="2">Class Method Details</th></tr>
</table>

<a name="read"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">read</span>(<span class=sig-arg>cls</span>,
          <span class=sig-arg>input_stream_or_filename</span>)</span>
  </h3>
  Read a graph from a dot file. May be called from either the Digraph 
  or Graph class; either way, the correct directed or undirected graph 
  object will be returned.
  <dl><dt></dt><dd>
  </dd></dl>
</td></tr></table>

<a name="from_bgl"></a>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>
  <h3><span class="sig"><span class="sig-name">from_bgl</span>(<span class=sig-arg>cls</span>,
          <span class=sig-arg>bgraph</span>,
          <span class=sig-arg>node_properties</span>=<span class=sig-default>[]</span>,
          <span class=sig-arg>edge_properties</span>=<span class=sig-default>[]</span>)</span>
  </h3>
  <p>Translate a boost.python graph into a yapgvb graph.</p>
  The returned translation_map behaves like a dictionary of all 
  corresponding (boost_edge, yapgvb_edge), (yapgvb_edge, boost_edge), 
  (boost_vertex, yapgvb_node), and (yapgvb_node, boost_vertex) key/value 
  pairs.
  <dl><dt></dt><dd>
    <dl><dt><b>Parameters:</b></dt>
      <dd><code><b>bgraph</b></code> -
         A boost.graph.Graph or boost.graph.Digraph instance
      <dd><code><b>node_properties</b></code> -
         A list of strings naming node properties to converted from 
        boost to yapgvb.
      <dd><code><b>edge_properties</b></code> -
         A list of strings naming edge properties to converted from 
        boost to yapgvb.
      </dd>
    </dl>
    <dl><dt><b>Returns:</b></dt>
      <dd>
        (ygraph, translation_map)
      </dd>
    </dl>
  </dd></dl>
</td></tr></table>
<br />


<!-- =========== START OF PROPERTY DETAILS =========== -->
<table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white">
<tr bgcolor="#70b0f0" class="details">
  <th colspan="2">Property Details</th></tr>
</table>
<table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="nodes"></a>
<h3>nodes</h3>
An iterator over all nodes in the graph
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="edges"></a>
<h3>edges</h3>
An iterator of edges contained in the graph.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="bb"></a>
<h3>bb</h3>
<p>Bounding box of drawing in integer points.</p>
description of rect type
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="bgcolor"></a>
<h3>bgcolor</h3>
<p>When attached to the root graph, this color is used as the background 
for entire canvas. When a cluster attribute, it is used as the initial 
background for the cluster. If a cluster has a filled style, the 
cluster's fillcolor will overlay the background color.</p>
If no background color is specified for the root graph, no graphics 
operation are performed on the background. This works fine for PostScript 
but for bitmap output, all bits are initialized to something. This means 
that when the bitmap output is included in some other document, all of 
the bits within the bitmap's bounding box will be set, overwriting 
whatever color or graphics where already on the page. If this effect is 
not desired, and you only want to set bits explicitly assigned in drawing 
the graph, set background=&quot;transparent&quot;.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="center"></a>
<h3>center</h3>
If true, the drawing is centered in the output canvas.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="charset"></a>
<h3>charset</h3>
Specifies the character encoding used when interpreting string input 
as a text label. The default value is &quot;UTF-8&quot;. The other legal 
value is &quot;iso-8859-1&quot; or, equivalently, &quot;Latin1&quot;. The 
charset attribute is case-insensitive. Note that if the character 
encoding used in the input does not match the charset value, the 
resulting output may be very strange.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="clusterrank"></a>
<h3>clusterrank</h3>
<p>Mode used for handling clusters. If clusterrank is &quot;local&quot;, 
a subgraph whose name begins with &quot;cluster&quot; is given special 
treatment. The subgraph is laid out separately, and then integrated as a 
unit into its parent graph, with a bounding rectangle drawn about it. If 
the cluster has a label parameter, this label is displayed within the 
rectangle. Note also that there can be clusters within clusters. At 
present, the modes &quot;global&quot; and &quot;none&quot; appear to be 
identical, both turning off the special cluster processing.</p>
Possible values: 'local', 'global', 'none'
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="colorscheme"></a>
<h3>colorscheme</h3>
This attribute specifies a color scheme namespace. If defined, it 
specifies the context for interpreting color names. In particular, if a 
color value has form &quot;xxx&quot; or &quot;//xxx&quot;, then the color 
xxx will be evaluated according to the current color scheme. If no color 
scheme is set, the standard X11 naming is used. For example, if 
colorscheme=bugn9, then color=7 is interpreted as 
&quot;/bugn9/7&quot;.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="comment"></a>
<h3>comment</h3>
Comments are inserted into output. Device-dependent
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="compound"></a>
<h3>compound</h3>
If true, allow edges between clusters. (See lhead and ltail 
below.)
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="concentrate"></a>
<h3>concentrate</h3>
If true, use edge concentrators.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="Damping"></a>
<h3>Damping</h3>
Factor damping force motions. On each iteration, a nodes movement is 
limited to this factor of its potential motion. By being less than 1.0, 
the system tends to ``cool'', thereby preventing cycling.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="defaultdist"></a>
<h3>defaultdist</h3>
This specifies the distance between nodes in separate connected 
components. If set too small, connected components may overlap. Only 
applicable if pack=false.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="dim"></a>
<h3>dim</h3>
Set the number of dimensions used for the layout. The maximum value 
allowed is 10.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="directed"></a>
<h3>directed</h3>
True if directed, False if not. Read-only.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="dpi"></a>
<h3>dpi</h3>
This specifies the expected number of pixels per inch on a display 
device. For bitmap output, this guarantees that text rendering will be 
done more accurately, both in size and in placement. For SVG output, it 
is used to guarantee that the dimensions in the output correspond to the 
correct number of points or inches.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="epsilon"></a>
<h3>epsilon</h3>
Terminating condition. If the length squared of all energy gradients 
are epsilon, the algorithm stops.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="fontcolor"></a>
<h3>fontcolor</h3>
Color used for text.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="fontname"></a>
<h3>fontname</h3>
<p>Font used for text. This very much depends on the output format and, 
for non-bitmap output such as PostScript or SVG, the availability of the 
font when the graph is displayed or printed. As such, it is best to rely 
on font faces that are generally available, such as Times-Roman, 
Helvetica or Courier.</p>
<p>If Graphviz was built using the fontconfig library, the latter library 
will be used to search for the font. However, if the fontname string 
contains a slash character &quot;/&quot;, it is treated as a pathname for 
the font file, though font lookup will append the usual font 
suffixes.</p>
If Graphviz does not use fontconfig, fontname will be considered the 
name of a Type 1 or True Type font file. If you specify fontname=schlbk, 
the tool will look for a file named schlbk.ttf or schlbk.pfa or 
schlbk.pfb in one of the directories specified by the fontpath attribute. 
The lookup does support various aliases for the common fonts.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="fontpath"></a>
<h3>fontpath</h3>
Directory list used by libgd to search for bitmap fonts if Graphviz 
was not built with the fontconfig library. If fontpath is not set, the 
environment variable DOTFONTPATH is checked. If that is not set, 
GDFONTPATH is checked. If not set, libgd uses its compiled-in font path. 
Note that fontpath is an attribute of the root graph.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="fontsize"></a>
<h3>fontsize</h3>
Font size, in points, used for text.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="graph"></a>
<h3>graph</h3>
graph to which this belongs (parent, if a subgraph, otherwise 
self)
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="K"></a>
<h3>K</h3>
Spring constant used in virtual physical model. It roughly corresponds 
to an ideal edge length (in inches), in that increasing K tends to 
increase the distance between nodes. Note that the edge attribute len can 
be used to override this value for adjacent nodes.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="label"></a>
<h3>label</h3>
Text label attached to objects. If a node's shape is record, then the 
label can have a special format which describes the record layout.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="labeljust"></a>
<h3>labeljust</h3>
Justification for cluster labels. If &quot;r&quot;, the label is 
right-justified within bounding rectangle; if &quot;l&quot;, 
left-justified; else the label is centered. Note that a subgraph inherits 
attributes from its parent. Thus, if the root graph sets labeljust to 
&quot;l&quot;, the subgraph inherits this value.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="labelloc"></a>
<h3>labelloc</h3>
Top/bottom placement of graph and cluster labels. If the attribute is 
&quot;t&quot;, place label at the top; if the attribute is &quot;b&quot;, 
place label at the bottom. By default, root graph labels go on the bottom 
and cluster labels go on the top. Note that a subgraph inherits 
attributes from its parent. Thus, if the root graph sets labelloc to 
&quot;b&quot;, the subgraph inherits this value.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="landscape"></a>
<h3>landscape</h3>
If true, the graph is rendered in landscape mode. Synonymous with 
rotate=90 or orientation=landscape.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="layers"></a>
<h3>layers</h3>
Specifies a linearly ordered list of layer names attached to the graph 
The graph is then output in separate layers. Only those components 
belonging to the current output layer appear. For more information, see 
the page How to use drawing layers (overlays).
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="layersep"></a>
<h3>layersep</h3>
Specifies the separator characters used to split the layers attribute 
into a list of layer names.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="levelsgap"></a>
<h3>levelsgap</h3>
Specifies strictness of level constraints in neato when 
mode=&quot;hier&quot;. Larger positive values mean stricter constraints, 
which demand more separation between levels. On the other hand, negative 
values will relax the constraints by allowing some overlap between the 
levels.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="lp"></a>
<h3>lp</h3>
Label position, in points.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="margin"></a>
<h3>margin</h3>
<p>For graphs, this sets x and y margins of canvas, in inches. If the 
margin is a single double, both margins are set equal to the given 
value.</p>
For nodes, this attribute specifies space left around the node's 
label. By default, the value is 0.11,0.055.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="maxiter"></a>
<h3>maxiter</h3>
Sets the number of iterations used.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="mclimit"></a>
<h3>mclimit</h3>
Multiplicative scale factor used to alter the MinQuit (default = 8) 
and MaxIter (default = 24) parameters used during crossing minimization. 
These correspond to the number of tries without improvement before 
quitting and the maximum number of iterations in each pass.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="mindist"></a>
<h3>mindist</h3>
Specifies the minimum separation between all nodes.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="mode"></a>
<h3>mode</h3>
<p>Technique for optimizing the layout. If mode is &quot;major&quot;, 
neato uses stress majorization. If mode is &quot;KK&quot;, neato uses a 
version of the gradient descent method. The only advantage to the latter 
technique is that it is sometimes appreciably faster for small (number of 
nodes &lt; 100) graphs. A significant disadvantage is that it may 
cycle.</p>
There is a new, experimental mode in neato, &quot;hier&quot;, which 
adds a top-down directionality similar to the layout used in dot.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="model"></a>
<h3>model</h3>
This value specifies how the distance matrix is computed for the input 
graph. The distance matrix specifies the ideal distance between every 
pair of nodes. neato attemps to find a layout which best achieves these 
distances. By default, it uses the length of the shortest path, where the 
length of each edge is given by its len attribute. If model is 
&quot;circuit&quot;, neato uses the circuit resistance model to compute 
the distances. This tends to emphasize clusters. If model is 
&quot;subset&quot;, neato uses the subset model. This sets the edge 
length to be the number of nodes that are neighbors of exactly one of the 
end points, and then calculates the shortest paths. This helps to 
separate nodes with high degree.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="nodesep"></a>
<h3>nodesep</h3>
Minimum space between two adjacent nodes in the same rank, in 
inches.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="nojustify"></a>
<h3>nojustify</h3>
By default, the justification of multi-line labels is done within the 
largest context that makes sense. Thus, in the label of a polygonal node, 
a left-justified line will align with the left side of the node (shifted 
by the prescribed margin). In record nodes, left-justified line will line 
up with the left side of the enclosing column of fields. If nojustify is 
&quot;true&quot;, multi-line labels will be justified in the context of 
itself. For example, if the attribute is set, the first label line is 
long, and the second is shorter and left-justified, the second will align 
with the left-most character in the first line, regardless of how large 
the node might be.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="normalize"></a>
<h3>normalize</h3>
If set, normalize coordinates of final layout so that the first point 
is at the origin, and then rotate the layout so that the first edge is 
horizontal.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="nslimit"></a>
<h3>nslimit</h3>
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="nslimit1"></a>
<h3>nslimit1</h3>
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="ordering"></a>
<h3>ordering</h3>
If &quot;out&quot; for a graph G, and n is a node in G, then edges 
n-&gt;* appear left-to-right in the same order in which they are defined. 
If &quot;in&quot;, the edges *-&gt;n appear left-to-right in the same 
order in which they are defined for all nodes n.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="orientation"></a>
<h3>orientation</h3>
Angle, in degrees, used to rotate node shapes.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="outputorder"></a>
<h3>outputorder</h3>
<p>Specify order in which nodes and edges are drawn.</p>
Possible values: 'breadthfirst', 'nodesfirst', 'edgesfirst'
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="overlap"></a>
<h3>overlap</h3>
<p>Determines if and how node overlaps should be removed. Nodes are first 
enlarged using the sep attribute. If &quot;true&quot; , overlaps are 
retained. If the value is &quot;scale&quot;, overlaps are removed by 
uniformly scaling in x and y. If the value converts to &quot;false&quot;, 
node overlaps are removed by a Voronoi-based technique. If the value is 
&quot;scalexy&quot;, x and y are separately scaled to remove overlaps. If 
the value is &quot;orthoxy&quot; or &quot;orthoyx&quot;, overlaps are 
moved by optimizing two constraint problems, one for the x axis and one 
for the y. The suffix indicates which axis is processed first. If the 
value is &quot;ortho&quot;, the technique is similar to 
&quot;orthoxy&quot; except a heuristic is used to reduce the bias between 
the two passes. If the value is &quot;ortho_yx&quot;, the technique is 
the same as &quot;ortho&quot;, except the roles of x and y are reversed. 
The values &quot;portho&quot;, &quot;porthoxy&quot;, 
&quot;porthoxy&quot;, and &quot;portho_yx&quot; are similar to the 
previous four, except only pseudo-orthogonal ordering is enforced.</p>
<p>If the value is &quot;compress&quot;, the layout will be scaled down 
as much as possible without introducing any overlaps, obviously assuming 
there are none to begin with.</p>
<p>Except for fdp, the layouts assume overlap=&quot;true&quot; as the 
default. Fdp first uses a number of passes using built-in, force-directed 
technique to remove overlaps. Thus, fdp accepts overlap with an integer 
prefix followed by a colon, specifying the number of tries. If there is 
no prefix, no initial tries will be performed. If there is nothing 
following a colon, none of the above methods will be attempted. By 
default, fdp uses overlap=&quot;9:portho&quot;. Note that 
overlap=&quot;true&quot;, overlap=&quot;0:true&quot; and 
overlap=&quot;0:&quot; all turn off all overlap removal.</p>
<p>Except for the Voronoi method, all of these transforms preserve the 
orthogonal ordering of the original layout. That is, if the x coordinates 
of two nodes are originally the same, they will remain the same, and if 
the x coordinate of one node is originally less than the x coordinate of 
another, this relation will still hold in the transformed layout. The 
similar properties hold for the y coordinates.</p>
NOTEThe methods &quot;orthoxy&quot; and &quot;orthoyx&quot; are still 
evolving. The semantics of these may change, or these methods may 
disappear altogether.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="pack"></a>
<h3>pack</h3>
<p>This is true if the value of pack is &quot;true&quot; 
(case-insensitive) or a non-negative integer. If true, each connected 
component of the graph is laid out separately, and then the graphs are 
packed tightly. If pack has an integral value, this is used as the size 
(in points) of a margin around each part; otherwise, a default margin of 
8 is used. If pack is interpreted as false, the entire graph is laid out 
together. The granularity and method of packing is influenced by the 
packmode attribute.</p>
For layouts which always do packing, such a twopi, the pack attribute 
is just used to set the margin.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="packmode"></a>
<h3>packmode</h3>
<p>This indicates the granularity and method used for packing (cf. 
packMode). Note that defining packmode will automatically turn on packing 
as though one had set pack=true.</p>
Possible values: 'node', 'clust', 'graph'
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="page"></a>
<h3>page</h3>
Width and height of output pages, in inches. If this is set and is 
smaller than the size of the layout, a rectangular array of pages of the 
specified page size is overlaid on the layout, with origins aligned in 
the lower-left corner, thereby partitioning the layout into pages. The 
pages are then produced one at a time, in pagedir order.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="pagedir"></a>
<h3>pagedir</h3>
<p>If the page attribute is set and applicable, this attribute specifies 
the order in which the pages are emitted. This is limited to one of the 8 
row or column major orders.</p>
Possible values: 'BL', 'BR', 'TL', 'TR', 'RB', 'RT', 'LB', 'LT'
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="quantum"></a>
<h3>quantum</h3>
If quantum &gt; 0.0, node label dimensions will be rounded to integral 
multiples of the quantum.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="rankdir"></a>
<h3>rankdir</h3>
<p>Sets direction of graph layout. For example, if 
rankdir=&quot;LR&quot;, and barring cycles, an edge T -&gt; H; will go 
from left to right. By default, graphs are laid out from top to 
bottom.</p>
Possible values: 'TB', 'LR', 'BT', 'RL'
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="ranksep"></a>
<h3>ranksep</h3>
In dot, this the gives desired rank separation, in inches. This is the 
minimum vertical distance between the bottom of the nodes in one rank and 
the tops of nodes in the next. If the value contains &quot;equally&quot;, 
the centers of all ranks are spaced equally apart. Note that both 
settings are possible, e.g., ranksep = &quot;1.2 equally&quot;. In twopi, 
specifies radial separation of concentric circles.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="ratio"></a>
<h3>ratio</h3>
<p>Sets the aspect ratio (drawing height/drawing width) for the drawing. 
Note that this is adjusted before the size attribute constraints are 
enforced.</p>
<p>If ratio is numeric, it is taken as the desired aspect ratio. Then, if 
the actual aspect ratio is less than the desired ratio, the drawing 
height is scaled up to achieve the desired ratio; if the actual ratio is 
greater than that desired ratio, the drawing width is scaled up.</p>
<p>If ratio = &quot;fill&quot; and the size attribute is set, node 
positions are scaled, separately in both x and y, so that the final 
drawing exactly fills the specified size.</p>
<p>If ratio = &quot;compress&quot; and the size attribute is set, dot 
attempts to compress the initial layout to fit in the given size. This 
achieves a tighter packing of nodes but reduces the balance and symmetry. 
This feature only works in dot.</p>
<p>If ratio = &quot;expand&quot;, the size attribute is set, and both the 
width and the height of the graph are less than the value in size, node 
positions are scaled uniformly until at least one dimension fits size 
exactly. Note that this is distinct from using size as the desired size, 
as here the drawing is expanded before edges are generated and all node 
and text sizes remain unchanged.</p>
If ratio = &quot;auto&quot;, the page attribute is set and the graph 
cannot be drawn on a single page, then size is set to an ``ideal'' value. 
In particular, the size in a given dimension will be the smallest 
integral multiple of the page size in that dimension which is at least 
half the current size. The two dimensions are then scaled independently 
to the new size. This feature only works in dot.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="remincross"></a>
<h3>remincross</h3>
If true and there are multiple clusters, run cross minimization a 
second time.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="resolution"></a>
<h3>resolution</h3>
This is a synonym for the dpi attribute.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="root"></a>
<h3>root</h3>
This specifies nodes to be used as the center of the layout and the 
root of the generated spanning tree. As a graph attribute, this gives the 
name of the node. As a node attribute (circo only), it specifies that the 
node should be used as a central node. In twopi, this will actually be 
the central node. In circo, the block containing the node will be central 
in the drawing of its connected component. If not defined, twopi will 
pick a most central node, and circo will pick a random node.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="rotate"></a>
<h3>rotate</h3>
If 90, set drawing orientation to landscape.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="samplepoints"></a>
<h3>samplepoints</h3>
If the input graph defines the vertices attribute, and output is dot 
or xdot, this give the number of points used to represent circles and 
ellipses. It plays the same role in neato, when adjusting the layout to 
avoid overlapping nodes.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="searchsize"></a>
<h3>searchsize</h3>
During network simplex, maximum number of edges with negative cut 
values to search when looking for one with minimum cut value.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="sep"></a>
<h3>sep</h3>
Fraction to increase polygons (multiply coordinates by 1 + sep) for 
purposes of determining overlap. Guarantees a minimal non-zero distance 
between nodes. If unset but esep is defined, sep will be set to esep/0.8. 
If esep is unset, the default value is used.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="showboxes"></a>
<h3>showboxes</h3>
Print guide boxes in PostScript at the beginning of routesplines if 1, 
or at the end if 2. (Debugging)
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="size"></a>
<h3>size</h3>
<p>Maximum width and height of drawing, in inches. If defined and the 
drawing is too large, the drawing is uniformly scaled down so that it 
fits within the given size.</p>
<p>If size ends in an exclamation point (!), then it is taken to be the 
desired size. In this case, if both dimensions of the drawing are less 
than size, the drawing is scaled up uniformly until at least one 
dimension equals its dimension in size.</p>
Note that there is some interaction between the size and ratio 
attributes.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="splines"></a>
<h3>splines</h3>
<p>Controls how, and if, edges are represented. If true, edges are drawn 
as splines routed around nodes; if false, edges are drawn as line 
segments. (Note: at present (1 Jan 2006), setting splines=false has no 
effect in dot.) If set to &quot;&quot;, no edges are drawn at all.</p>
By default, the attribute is unset. How this is interpreted depends on 
the layout. For dot, the default is to draw edges as splines. For all 
other layouts, the default is to draw edges as line segments. Note that 
for these latter layouts, if splines=&quot;true&quot;, this requires 
non-overlapping nodes (cf. overlap). If fdp is used for layout and 
splines=&quot;compound&quot;, then the edges are drawn to avoid clusters 
as well as nodes.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="start"></a>
<h3>start</h3>
<p>Parameter used to determine the initial layout of nodes. By default, 
nodes are randomly placed in a unit square. The same seed is always used 
for the random number generator, so the initial placement is 
repeatable.</p>
Possible values: 'regular', 'self', 'random'
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="strict"></a>
<h3>strict</h3>
True if strict, False if not. Read-only.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="stylesheet"></a>
<h3>stylesheet</h3>
A URL or pathname specifying an XML style sheet, used in SVG 
output.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="target"></a>
<h3>target</h3>
If the object has a URL, this attribute determines which window of the 
browser is used for the URL. See W3C documentation.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="truecolor"></a>
<h3>truecolor</h3>
<p>If set explicitly to true or false, the value determines whether or 
not internal bitmap rendering relies on a truecolor color model or uses a 
color palette. If the attribute is unset, truecolor is not used unless 
there is a shapefile property for some node in the graph. The output 
model will use the input model when possible.</p>
<p>Use of color palettes results in less memory usage during creation of 
the bitmaps and smaller output files.</p>
Usually, the only time it is necessary to specify the truetype model 
is if the graph uses more than 256 colors. However, if one uses 
bgcolor=transparent with a color palette, font antialiasing can show up 
as a fuzzy white area around characters. Using truecolor=true avoids this 
problem.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="URL"></a>
<h3>URL</h3>
<p>Hyperlinks incorporated into device-dependent output. At present, used 
in ps2, cmap, i*map and svg formats. For all these formats, URLs can be 
attached to nodes, edges and clusters. URL attributes can also be 
attached to the root graph in ps2, cmap and i*map formats. This serves as 
the base URL for relative URLs in the former, and as the default image 
map file in the latter.</p>
<p>The active area for a node or cluster is its bounding box. For edges, 
the active areas are small circles where the edge contacts its head and 
tail nodes. These areas may overlap the related node, and the edge URL 
dominates. If the edge has a label, this will also be active. Finally, if 
the edge has a head or tail label, this will also be active. Note, 
however, that if the edge has a headURL attribute, it is this value that 
is used near the head node and on the head label, if defined. The similar 
restriction holds when tailURL is defined.</p>
The URL of the root graph is only treated as an escString if the 
output format is cmap.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="viewport"></a>
<h3>viewport</h3>
Clipping window on final drawing.
</td></tr></table><table width="100%" class="func-details" bgcolor="#e0e0e0"><tr><td>

<a name="voro_margin"></a>
<h3>voro_margin</h3>
</td></tr></table><br />


<!-- =========== START OF NAVBAR =========== -->
<table class="navbar" border="0" width="100%" cellpadding="0" bgcolor="#a0c0ff" cellspacing="0">
  <tr valign="center">
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="yapgvb-module.html">Home</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="trees.html">Trees</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="indices.html">Index</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar">&nbsp;&nbsp;&nbsp;<a class="navbar" href="help.html">Help</a>&nbsp;&nbsp;&nbsp;</th>
    <th class="navbar" align="right" width="100%">
      <table border="0" cellpadding="0" cellspacing="0">
      <tr><th class="navbar" align="center">
        <p class="nomargin">
          yapgvb
      </p></th></tr></table>
    </th>
  </tr>
</table>

<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tr>
    <td align="left"><font size="-2">Generated by Epydoc 2.1 on Tue Feb 21 14:34:48 2006</font></td>
    <td align="right"><a href="http://epydoc.sourceforge.net"
                      ><font size="-2">http://epydoc.sf.net</font></a></td>
  </tr>
</table>
</body>
</html>
